For school, we created on an animation in a smaller group. Our group is called Studio Sloth. We are a group of 6 people, where each of us has a (slightly) different role. I worked on the concept art (together with somebody else), and I will design and paint the backgrounds.
Our animation is about an explorer, Pedro, who is in search of a golden hourglass. He finds the hourglass in an ancient temple, which - unbeknownst to him - is surrounded by a civilization of sloths. The hourglass turns out to be a magic artifact, which can control the speed of the sloths. Pedro tries to escape from the sloths with the hourglass, but runs into some resistance.
Some early sketches of sloths, plants and the relief that can be found within the temple:
Some sketches of different parts of a town that we were originally going to have around the temple. We ended up scrapping this idea, because we felt it didn't add anything to the story.
Some concept art for the jungle and temple:

Basic Colour Script:
Some of the final backgrounds:
The final animation: